Vacuum producing apparatus



No. 6H,455. Patented Sept. 27, I898;

w. E. MAY.

VACUUM PRODUCING APPARATUS.

(Application filed Aug. 12, 1897.)

(No Model.) 5 Sheets-Shaet I- In! 11am: PETERS co, PHOYO-LIYHONWASmHGTON. a c.

N0. 6|l,455. Patented Sept. 27, I893.

W. E. MAY. A

VACUUM PRODUCING APPARATUS.

5 Sheets-Sheet 2.

III]! IIIIL (Application filed Aug. 12, 1897.)

(No Model.)

m: uoams PETERS cov PMDYG-LH'MO, wAsnmorcw n No. 6|I,455.

Patented Sept. 27, I898. W. E. MAY.

VACUUM PRODUCING APPARATUS.

(Application filed Aug. 12. 1897-) 5 Sheets-Sheet 3.

(N0 Model.)

Zia 6250f.

No. 61!,455. Patented Sept. 27, I898. W. E. MAY.

VACUUM PRODUCING APPARATUS.

(Application filed Aug. 12, 1897.)

(No Model.) 5 Sheets-Sheet 4.

K it l0 UL JQMW m: wzmms Pawns co, Pnwoumu, msnmc'rom u c.

Patented Sept. 27, I898.

W. E. HAY.

.VAGUUM PRODUCING APPARATUS.

(Application filed Aug. 12, 1897.)

5 Sheets-Sheet 5.

(No Model.)

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v S'rarn PATENT Orricn.

W'ILLIAM ELLIS MAY, OF LONDON, ENGLAND, ASSIGNOR TO THE ELLIS MAY VACUUMSTEEL SYNDICATE, LIMITED, OF SAME PLACE.

JACUUM-PRODUClNG APPARATUS.

SFECIFIGATION forming part of Letters Patent No. 611,455, datedSeptember 27, 1898.

Application filed August 12,1897. Serial No. 648,062. (No model.)Patented in France March 3,1897,N0.264,642, and in Belgium March10,189'7,N0.1Z6,877-

T0 (tZZ whom it may concern.-

Be it known that 1, WIL IAM ELLIS MAY, a subject of the Queen of GreatBritain, residing at Bromley, London, in the county of Kent, England,have invented new and useful Improvements in Vacuum-Producing Apparatus,(for which I have obtained patents in France, No. 264,612, dated March3, 1897, and in Belgium, No. 126,877, dated March 10, 1897,) of whichthe followingis a specification.

This invention relates to improvements in vacu um-producin g apparatus.In apparatus which has been hitherto usually employed for this purposethe rarefaction of the air has been effected by the movement of a pistonin a cylinder connected with the chamber in which the vacuum is to beproduced, and it is well known that with ordinary apparatus of this kindit is not possible to obtain a complete vacuum in spaces or chambers ofany size, chiefly owing to the fact that the piston works against apressure (usually that of the atmosphere) and that a clearance-space isleft between the piston and the cover or end of the cylinder in which itmoves,which space at the end of the compression stroke of the piston isfilled with air at the pressure of the chamber into which the air isforced from the cylinder, such pressure being, as above mentioned,usually that of the atmosphere. On the next suction stroke of the pistonthis air expands and mixes with the air drawn from the chamber to beexhausted, and, it will be obvious that air will be continued to bedrawn from the said chamber until the pressure therein is equal to thatof a quantity of air which when the piston is at the end of its outwardstroke fills the cylinder and which when compressed by the said pistoninto the clearance-space between the piston and the cover of thecylinder has a pressure equal to that of the atmosphere.

Now it is the object of my invention to provide means whereby a moreperfect vacuum can be obtained than with apparatus of the kind abovedescribed; and to this end I combine with a novel construction ofexhauster hereinafter described an auxiliary pump or exhauster,whereby,notwithstanding that the air is reduced to such low tenuity in theexhauster that its piston has to travel nearly or quite to the end ofits stroke before producin g a pressure of air inside the exhausterequal to or greater than that of the atmosphere outside, the tenuity ofthe air will be still further reduced, the piston of the auxiliary pumpbeing so arranged relatively with the piston of the exhauster thatimmediately the exhauster-piston reaches the end of its compressionstroke the plunger or piston of the auxiliary pump makes its compressionstroke to force out the air in front of it. This compound action willallow the air to be reduced to a very low tenuity in a short time.

The auxiliary pump may be provided with springs to act as buffers ateach end of the stroke and may be driven by any suitable motor thestarting and stopping mechanism of which is connected to the rodsprojecting into the path of the exhauster-piston.

In the accompanying drawings, Figure 1 represents a vertical sectionalview of an apparatus embodying my invention, taken through the mainexhauster,tl1e store vacuumchamber being shown in elevation. Fig. 2represents a top plan view of the main exhauster and auxiliary pumps andtheir connections, the store vacuum-chamber being removed. Fig. 3 is anend elevation of the devices shown in Fig. 2. Fig. 4 is a section online at 4, Fig. 2. Figs. 5 and 6 are enlarged side and end views,respectively, of the valves interposed between the main exhauster andthe auxiliary pumps. Figs. 7 and 8 are r espectively a side elevationand top plan of a modified form of apparatus, showing a main exhausterof different construction from that shown in the preceding figures.Figs. 9 and 10 are sections, respectively, on the lines 9 9 and 10 10 ofFig. 8, said sections being drawn to a larger scale. Figs. 11 and 12 arefront views of the valves shown in Figs. 9 and 10.

Similar letters of reference indicate the same or corresponding partsthroughout the drawings.

In the form of my invention shown in Figs. 1 to 5, inclusive, n is thecylinder of the main exhauster, and u n are the inlet and outlet valves,respectively, of the same. The piston n in this instance isdouble-acting and is actuated by screws 0 0, driven from the shaft 0 ofa reversing steam-engine 0 or other motor through the medium ofgear-wheels 0 o 0 In the arrangement illustrated in Figs. 7 and S theexhauster is formed of two singleacting pumps mwith a steam cylinder 19placed between them, the pistons 01 of the pumps being connected to anddriven by the piston 13 of the steam-engine.

Referring again to the arrangement illustrated in Figs. 1 to 6, q q arethe rods projecting through the covers of the exhauster into the path ofthe piston 01 the said rods being connected by the levers q and rod g sothat they are simultaneously actuated. One of the said rods q isconnected to the slide-valve of a steam-cylinder r, the piston of whichis connected by a rod 0 to a clutchlever s, engaging with a clutch s.The clutch s is designed to engage with either of two sets of clutch-teeth upon bevel gearwheels 25 t, which wheels both gear with anotherbevel-wheel 15 mounted upon the shaft i carrying the fiy-wheel t of themotor 0 u u are a rod and lever connecting the clutch-lever s and thereversing mechanism a of the motor 0 Assuming the parts of the mechanismto be in the position shown in Fig. 1 and the piston 02 and thefly-wheel t to be moving in the direction of the arrows, when the pistonn arrives at the end of its stroke it will come into contact with therod q, projecting into its path, whereby steam will be admitted to theleft-hand end of the steamcylinder 7' and the piston of the latter willbe caused to move the clutch-lever s, so as to disengage the clutch sfrom the wheel 25 and engage it with the wheel t. The momentum of thefly-wheel t then instantaneously reverses the movement of the shaft 0,and consequently that of the piston a the movement of the clutch-lever sat the same time actuating the rod u and lever u, to reverse the engine.A similar operation of the parts will take place when the piston narrives at the other end of its strokethat is to say, the other rod qwill be actuated and operate the steam-valve of the cylinder 4', so asto cause its piston to move in the opposite direction to thathereinbefore described, whereby the clutch s will be disengaged from thewheel t and caused to engage with the wheel 15, the momentum of thefly-wheel t instantly reversing the movement of the shaft 0. In Figs. 7and 8 the reversal of the piston n is effected by the auxiliary pump inconnection therewith, as hereinafter described.

In Fig. l I have shown a store vacuumchamber 2 in connection with theexhauster, pipes 12 '12 passing to the inlet-valves n.

w w, Figs. 2, 3, 7, and 8, are the cylinders of the auxiliary pump whichI use in connection with my air-pump or exhauster, this pump beingsimilar in construction to the exhauster shown in Figs. 7 and S andactuated in a similar manner by a steam-cylinder 50, arranged betweenthe cylinders. In Figs. 2 and 3 the cylinders 10 are connected by twopipes w to the ends of the exhauster, outlet-valves n from the exhausterbeing arranged at the points 10 10 while in Figs. 7 and 8 only one pipe'10 with valves is shown in connection with each cylinder 20 of theauxiliary pump.

In the construction shown in Figs. 2 and 3 the auxiliary pump isactuated from ,the exhauster by the following means-that is to say, therod (1 is connected to the slide-valve rod 00 of the steam-cylinder 00through the medium of the bell-crank 00 rod :0 crank m shaft .92 crank:8 and rod 00 lVith this arrangement it will be seen that when the airis reduced to a low tenuity in the exhauster and the piston is travelingin the direction of the arrow, Fig. 2, the said piston will have totravel nearly to the end of its stroke before it produces a pressure ofthe air inside the exhauster equal to or greater than that of theatmosphere outside. The movement of the piston will cause the valve atthe points 10 102 to open and allow the air, which is gradually becomingmore dense as the piston 11 nears the end of its stroke, to pass intothe cylinder it, which is practically exhausted of air, as hereinafterdescribed. When the piston arrives at the end of its stroke and operatesthe rod g the slide-valve of the steam-cylinder x will be operated andwill admit steam to the said cylinder, so as to drive its piston, andthereby the piston contained in the cylinder 20, toward the left hand,thus expelling the contents of the cylinderw through the outlet-valve 20Asimilar operation takes place in connection with the other cylinder '10when the piston n of the exhauster arrives at the end of the returnstroke, the said operation also effecting the return stroke of thepiston of the first cylinder, which is thus emptied of air behind thesaid piston. It will therefore be seen that with my combination of mainand auxiliary exhausters the cylinder of the main exhauster is always incommunication with a practical vacuum in one of the cylinders of theauxiliary exhauster, so that during each compression stroke of the mainpiston the latter has only to compress the air in front of itsufficiently to open the valve leading into the auxiliary cylinder andnot to a pressure equal to that of the atmosphere, the piston-strokeconsequently being effective for the greater part of its length insteadof (as is usually the case) for a small portion only of the length.-

In Figs. 7 and 8 the devices g, which are actuated by the pistons u takethe form of levers connected together by the rod (1 the motion of whichis communicated to the slidevalve of the steam-cylinder x by a lever y.The reverse movement of the piston n is, however, caused by theauxiliary pump as follows-that is to say, rods or arms .2 are arrangedin the paths of the pistons of the cylinders it, the said rods beingmounted upon a bar 2', adapted to slide in bearings .2 when the arms aremoved by the said pistons. This rod .2 is connected by a lever z" to theslide-valve of the steam-cylinder p of the exhauster. It will thus beseen that when either of the pistons of the cylinders it) moves inwardlyit will come into contact with one of the arms 2, thereby actuating theslide-valve of the steam-cylinder p to admit steam, so as to drive thepiston 19 in the opposite direction to that in which the pistons of thecylinders to have been moved, and so on.

.2 .2, Figs. 2, 7, and S, are springs arranged to act as buffers,against which the pistons of the main and auxiliary exhausters (shown inFigs. 7 and S) strike at the end of their inward strokes.

It will be obvious that instead of providing the auxiliary exhausterwith two pumps in alinement with one another I can employ a singledouble-acting pump.

Having now particularly described and ascertained the nature of my saidinvention and in what manner the same is to be performed, I declare thatwhat I claim is 1. In apparatus for producing a vacuum, the combinationwith a main exhauster having a reciprocating piston, of an auxiliarypump communicating with the main exhauster, operating mechanism for saidauxiliary pump and means for controlling said operating mechanism by themovements of the main-exhauster piston, substantially as described.

2. In an apparatus forproducinga vacuum, the combination with the mainexhauster and its reciprocating piston, of an auxiliarypumpcommunicating with the main exhauster, operating mechanism for theauxiliary pump and controlling devices for said operating mechanismhaving a part extending into the path of the main-exhauster piston,substantially as described.

3. In apparatus for producing a vacuum, the combination with the mainexhauster and its reciprocating piston, of an auxiliarypumpcommunicating therewith, a check-valve interposed between the mainexhauster and the auxiliary pump,independent operatingmechanism for saidauxiliarypump and controlling devices for said mechanism, operated bythe piston of said main exhauster, substantially as described.

-l. In apparatus for producing a vacuum, the combination with the mainexhausterhaving a reciprocating iston, of an auxiliary pump communicatinwith the main exhauster on opposite sides of its piston, an operatingdevice for said auxiliary pump and controlling devices for saidoperating device operated by the piston of the main exhauster,substantially as described.

5. In apparatus for producing a vacuum, the combination with the mainexhauster hav ing a reciprocating piston, of an auxiliary pump providedwith two cylinders and a piston in each cylinder, said cylinderscommunicating with the main exhauster on opposite sides of its piston, asingle operating device for said auxiliaiy-pump pistons, and controllingdevices for said operating device, operated by the main-exhausterpiston, substantially as described.

6. In a vacuum-producing apparatus, the combination with a mainexhauster provided with a reciprocating piston, of an auxiliary pumphaving two cylinders connected independently to said exhauster atopposite sides of its piston, and a piston in each of said cylinders, asingle operating device intermediate said pistons and connected to eachof the same, and controlling devices for said operating device having apart extending into the path of the main-exhauster piston, substantiallyas described.

7. In apparatus for producing a vacuum, the combination with a mainair-pump or exhauster, of an auxiliarypump comprising two cylinders withpistons arranged in alinement with one another and having asteam-cylinder between them the piston of which is connected to thepistons of the two cylinders and of means whereby the movement of thesteamcylinder piston is controlled by the movement of the piston of themain exhauster, substantially as described.

8. In apparatus for producing a vacuum, the combination of a main pumporexhauster and of an auxiliary exhauster comprising two cylinders, thepistons of which are connected to the piston of an intermediatesteam-cylinder, of valve-controlled pipes by means of which eachpump-cylinder is placed in communication with each end of the cylinderof the main exhauster and of means whereby the motion of thesteam-piston is controlled through the medium of the piston of the mainexhauster, substantially as described.

9. In apparatus for producing a vacuum, the combination with anauxiliary air-pump or exhauster, of a main air-pump or exhausterconsisting of a pair of cylinders arranged in alinement with oneanother, a steam-cylinder arranged between the two pump-cylinders, thepiston of which steam-cylinder is con= nected to the two pistons of thepump-cylin= ders, and operative connections between said main exhausterand the auxiliary pump whereby the said auxiliarypump is controlled bythe movements of the main exhauster, substantially as described.

10. In apparatus for producing a vacuum, the combination of a mainexhauster, comprising two air-pumps and an intermediate steam-cylinderthe piston of which is connected to the two pistons of the said air=pumps, with an auxiliary exhauster also con sisting of two cylinders,the pistons of which are connected to the pistons of an intermediatestea1ncylinder, the pumps of the main exhauster being each connectedwith one of the cylinders of the auxiliary exhauster, and operativeconnections between the main exhauster and the steam-cylinder of theauxiliary exhaust-er, whereby the said steam-cylinder is controlled bythe movements of the main exhauster substantially as described.

11. In a vacuum-producing apparatus, the combination with the mainexhauster comprising two cylinders, a piston in each, an intermediatesteam-cylinder, and a piston therein connected with theexhauster-pistons, of an auxiliary pump connected with theexhauster-cylinders, an operating device for said pump, and controllingdevices for said pump operated by the pistons of the main exhauster,substantially as described.

12. In a vacuum-producing apparatus, the combination with the mainexhauster comprising two cylinders, a piston in each, an intermediatesteam-cylinder, and a piston therein connected with theexhauster-pistons, of an auxiliary pump comprising two pumping-cylinderseach communicating with one of the main-exhauster cylinders, andprovided with a piston, and an intermediate steam-cylinder provided witha piston connected with said auxiliary-pump pistons, and controllingdevices for said auxiliary steam cylinder and piston having partsextending into the paths of the main-exhauster pistons, substantially asdescribed.

13. In apparatus for producing a vacuum, the combination with a mainexhauster comprising two pump-cylinders the pistons of which areconnected to the piston of an intermediate steam-cylinder, of anauxiliary exhauster also comprising two pumps, the pistons of which areconnected to the pistons of an intermediate steam-cylinder, ofvalvecontrolled pipes placing one end of each of the main cylinders incommunication with one end of each corresponding auxiliary cylinder, ofmeans whereby the motion of the steam-piston of the main exhauster iscontrolled by the motion of the pistons of the auxiliary exhauster andof means whereby the motion of the auxiliary steam-piston is controlledby the movement of the pump-pistons of the main exhauster, substantiallyas described.

14:. Apparatus for producinga vacuum consisting of a main exhausterhaving two cylinders n n, the pistons of which are connected to thepiston of an intermediate steam-cylinder p and of an auxiliary exhausteralso consisting of two cylinders 20 w, the pistons of which areconnected to the piston of an intermediate steam cylinder w and one endof each of which is connected to one end of the corresponding cylinderof the main exhauster, of the levers and rods q g y whereby theauxiliary steam-piston is controlled by the motion of the main pistons91 and of the rods and levers z, a 2 2 whereby the motion of thesteam-piston is reversed by the pistons of the auxiliary pump-cylinders,substantially as described.

WILLIAM ELLIS HAY.

Witnesses:

G. F. REDFERN, O. G. REDFERN.

